An epidemiologic study is proposed of Mohawk women and infants to test the hypotheses that exposure to polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polynuclear aromatic hydrocarbons (PAHs) from a nearby Superfund hazardous waste site elevates body burdens and affects the cytochrome P-450-dependent mixed function monooxygenase system. Exposure and body burdens will be assessed by: 1) estimating cumulative maternal dose from ingestion, inhalation, and dermal contact; 2) measuring concentrations of 68 routine PCB congeners in serum and urine, and, if lactating, of an additional 12 coplanar PCB congeners and of 34 PCDD/F congeners and 15 PAHs in breast milk; and 3) measuring infant concentrations of the PCB congeners in cord serum and urine and output of the PCDD/F congeners in feces. P-450IA2 activity in the mothers and infants will be assessed through a caffeine breath test, a safe and noninvasive procedure that measures the rate at which labelled carbon dioxide is exhaled as an indirect monitor. Pregnant Mohawk women will be interviewed and invited to participate in maternal blood sampling during their second trimester and cord blood sampling at delivery. They will also be asked to provide blood, urine, and breast milk samples and to collect infant urine and feces in cloth diapers at 1, 3, and 6 months post-partum to investigate change in pollutant levels over time. Multivariable statistical techniques will be used: 1) to test for differences in the mean contaminant levels of mothers according to cumulative dose and of infants according to breast-feeding status; 2) to relate breast milk pollutant concentrations to maternal and infant urinary levels and infant fecal output; and 3) to correlate P-450IA2 activity with levels of PCB and PCDD/F congeners and PAHs. A novel statistical technique based on summary scores will be used to "fingerprint" the waste site as a point source. The results will significantly enhance our understanding of how important classes of chemicals arising from hazardous waste bioaccumulate in human adults and infants and whether P-450IA2 induction is a sensitive biomarker of their early biologic effect.